JP2016099523A - Lens barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens barrel having satisfactory optical characteristics.SOLUTION: An interchangeable lens 100 includes a fixed frame 60 in which a front movable lens group 4 and a rear movable lens group 6 are coaxially arrayed and movably housed in an optical axis O direction. An intermediate member 40 is disposed between a movable space of the lens frame 11 holding the movable lens group 4 and a movable space of the lens frame 12 holding the movable lens group 6. The intermediate member separates the movable lens groups 4 from the movable lens group 6 to prevent them from interfering with each other, and blocks unnecessary light among light that is incident to the fixed frame 60 and passes through the front movable space to reach the rear movable space.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a lens barrel having, for example, two lens groups that are movable in the optical axis direction.

  For example, as a lens barrel, an interchangeable lens for a camera provided with two sets of actuators that respectively move two sets of lens groups in the optical axis direction is known. Each of the two sets of actuators includes a voice coil motor including a coil fixed to a movable member holding a lens group, a magnet fixed to the outer frame side facing the coil, and a yoke for forming a magnetic circuit ( VCM).

  When a current is passed through the coil of the VCM, the movable member moves in the optical axis direction along the yoke by electromagnetic induction.

JP 2000-147350 A

However, in a state where no current is passed through the coil, the movable member can freely move along the yoke. For this reason, a partition plate is required between the two movable members.
If the coil is provided so as to be movable with respect to the yoke, unnecessary light is transmitted through the gap between the coil and the yoke. This light becomes harmful light that does not pass through the two lens groups in succession, and adversely affects the captured image of the camera.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a lens barrel that prevents a lens from colliding when not energized and has good optical characteristics when energized.

  In one aspect of the lens barrel of the present invention, the first movable member holding the first lens group and the second movable member holding the second lens group are arranged in the optical axis direction so as to be movable with respect to the fixed frame. The lens barrel includes a first coil, a first magnet disposed opposite to the first coil, and a first yoke to form a first magnetic circuit, and the first magnetic circuit forms the first magnetic circuit. The first magnetic circuit is magnetically separated by a first actuator that moves the movable member in the optical axis direction, a second coil, a second magnet disposed opposite to the second coil, and a second yoke. An independent second magnetic circuit is configured, and the second magnetic circuit moves the second movable member in the optical axis direction between the first movable member and the second movable member. The first lens group And an intermediate member having a stop portion serving as a stop of an optical system including the second lens group and a collision preventing portion for preventing the first movable member and the second movable member from colliding with each other. It is characterized by.

  According to the lens barrel of the present invention, it is possible to prevent a lens from colliding when not energized and to provide a lens barrel having good optical characteristics when energized.

FIG. 1 is an external view of an interchangeable lens according to the embodiment. FIG. 2 is a longitudinal sectional view of the interchangeable lens of FIG. FIG. 3 is a cross-sectional view showing an assembly in which two sets of movable lens groups, a support mechanism, two sets of actuators, and an intermediate member assembled in the interchangeable lens shown in FIG. 2 are assembled. FIG. 4 is a perspective view showing the assembly of FIG. FIG. 5 is a perspective view of the assembly of FIG. 4 viewed from another direction. 6 is a perspective view showing a fixed frame for attaching the assembly of FIG. 5 to the interchangeable lens of FIG. FIG. 7 is a perspective view showing a first yoke attached to the fixed frame of FIG. 8 is a perspective view showing a state in which the first yoke of FIG. 7 is attached to the fixed frame of FIG. FIG. 9 is a partial cross-sectional view taken along F9-F9 in FIG. FIG. 10 is a perspective view showing a state in which the front lens frame is incorporated. FIG. 11 is a perspective view showing the third yoke. FIG. 12 is a perspective view showing a state in which the third yoke of FIG. 11 is attached. FIG. 13 is a perspective view showing a state in which the intermediate member is attached. FIG. 14 is a perspective view showing a state in which the rear lens frame is attached. FIG. 15 is a perspective view showing the second yoke. FIG. 16 is a perspective view showing a state in which the second yoke of FIG. 15 is incorporated in the fixed frame. 17 is a partial cross-sectional view taken along F17-F17 in FIG. FIG. 18 is a perspective view for explaining the layout of the buffer member. FIG. 19 is a cross-sectional view for explaining the layout of the buffer member. FIG. 20 is a schematic view of the assembly with the front lens frame removed, as viewed from the front. FIG. 21 is a schematic view of the assembly with the rear lens frame removed, as viewed from the rear. FIG. 22 is a cross-sectional view for explaining a structure for shielding light passing between the yoke and the coil. FIG. 23 is a cross-sectional view for explaining a structure for shielding light reflected by the yoke. FIG. 24 is a ray diagram of light incident on the fixed frame.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is an external view showing an interchangeable lens 100 which is an embodiment of a lens barrel of the present invention. 2 is a longitudinal sectional view of the interchangeable lens 100 of FIG. 1 cut along a plane including the optical axis O thereof. The interchangeable lens 100 is, for example, an interchangeable lens that is detachably attached to a digital camera (not shown), and includes two sets of movable lens groups 4 and 6 to be described later. In the following description, a subject side (not shown) along the optical axis O is referred to as the front, and a camera body side (not shown) (not shown) is referred to as the rear.

  The interchangeable lens 100 has a substantially cylindrical outer frame 1 whose outer diameter slightly increases toward the front along the optical axis O. A plurality of sets of fixed lens groups 2 that are separated from each other along the optical axis O are fixed inside the outer frame 1. In addition, two sets of movable lens groups 4 and 6 that are movable in the front-rear direction along the optical axis O are provided in the outer frame 1. The movable lens groups 4 and 6 are assembled into a fixed frame 60 (FIG. 6) described later and attached to the inside of the outer frame 1. The lens groups 2, 4, and 6 are provided coaxially so that the optical axis O passes through the center thereof.

  FIG. 3 shows a support mechanism 10 that supports two sets of movable lens groups 4 and 6 movably in the optical axis O direction, an actuator 20 (first actuator) that drives the front movable lens group 4, and a rear movable lens group. 6 is an enlarged cross-sectional view showing an assembly 50 in which an actuator 30 (second actuator) that drives 6 and an intermediate member 40 (throttle part, collision prevention part) are combined. 4 is a perspective view showing the assembly 50 of FIG. 3, and FIG. 5 is a perspective view of the assembly 50 of FIG. 4 viewed from a direction different from FIG. In FIG. 4, the intermediate member 40 is not shown for easy understanding of the structure. The assembly 50 is assembled in a fixed frame 60 described later and attached in the outer frame 1.

  The support mechanism 10 supports the lens frame 11 (first movable member) holding the front movable lens group 4 (first lens group) so as to be movable in the direction of the optical axis O, and the rear movable lens group 6 (first lens). The lens frame 12 (second movable member) holding the two lens groups) is supported so as to be movable in the optical axis O direction. The actuator 20 drives the front lens frame 11 supported by the support mechanism 10 in the front-rear direction along the optical axis O. The actuator 30 drives the rear lens frame 12 supported by the support mechanism 10 in the front-rear direction along the optical axis O. The intermediate member 40 divides the movable region (first movable region) of the lens frame 11 by the actuator 20 and the movable region (second movable region) of the lens frame 12 by the actuator 30 and passes through the first movable region and is second movable. Unnecessary light is blocked out of light incident on the region.

  More specifically, the support mechanism 10 includes a lens frame 11 that holds the front movable lens group 4 and a lens frame 12 that holds the rear movable lens group 6. The two lens frames 11 and 12 are arranged side by side in the optical axis O direction in a posture along a plane orthogonal to the optical axis O. An intermediate member 40 is disposed between the movable region of the front lens frame 11 and the movable region of the rear lens frame 12 to prevent the two movable lens groups 4 and 6 from contacting each other. Also, a buffer member (not shown) is provided at the front end of the movable region of the front lens frame 11 and the rear end of the movable region of the rear lens frame 12, and the range of the movable region of each lens frame 11, 12. Is limited.

  The support mechanism 10 has three guide shafts 13, 14, and 15 having a circular cross section for holding the two lens frames 11 and 12 so as to be movable in the direction of the optical axis O. These three guide shafts 13, 14, 15 extend in parallel to the optical axis O in the vicinity of the inner surface of the fixed frame 60 and are fixed to the fixed frame 60. The two guide shafts 14 and 15 are provided on the opposite side of the guide shaft 13 and spaced apart from each other in the radial direction of the lens. The diameter of the guide shaft 13 is smaller than the diameter of the guide shafts 14 and 15.

  One guide shaft 13 having a small diameter holds the two lens frames 11 and 12 movably. One guide shaft 14 having a large diameter holds the front lens frame 11 movably. The other guide shaft 15 having a larger diameter holds the rear lens frame 12 movably. In other words, the front lens frame 11 is movably held by the two guide shafts 13 and 14, and the rear lens frame 12 is movably held by the two guide shafts 13 and 15. .

  On the other hand, the front lens frame 11 has a U-shaped fitting groove 11 a that fits into the guide shaft 13, and the rear lens frame 12 has a U-shaped fitting groove 12 a that fits into the guide shaft 13. Have Further, the front lens frame 11 has a through hole 11 b through which the guide shaft 14 is inserted, and the rear lens frame 12 has a through hole 12 b through which the guide shaft 15 is inserted. The through hole 11b of the lens frame 11 is provided on the opposite side of the fitting groove 11a that is spaced in the radial direction of the lens, and the through hole 12b of the lens frame 12 is provided in the radial direction of the lens with respect to the fitting groove 12a. It is provided on the opposite side.

  The actuator 20 for driving the front movable lens group 4 has two sets of driving units spaced apart from each other in the radial direction of the lens, and the actuator 30 for driving the rear movable lens group 6 has a lens diameter. It has two sets of drive units that are opposed to each other in the direction. Since one drive unit has the same structure and functions in the same manner as the other drive unit, only one drive unit will be described, and description of the other drive unit will be omitted.

  An actuator 20 for driving the front lens frame 11 is fixed on the fixed frame 60 side so as to face the outside of the first coil 21 fixed to the outer edge portion of the lens frame 11 and to be opposed to the outside of the first coil 21. The first magnet 22 and a first yoke 23 that cooperates with the first magnet 22 and the first coil 21 to form a first magnetic circuit. The actuator 20 has a third yoke 24 provided in contact with an end portion of the first yoke 23 facing a second yoke 33 described later. The third yoke 24 constitutes a part of the first magnetic circuit.

  The first yoke 23 has a U-shaped cross-section in which an end portion on the side (front side) separated from the second yoke 33 described later is folded, and has a structure in which a substantially rectangular magnetic plate is folded in half from the center. More specifically, the first yoke 23 includes a first portion 23a fixed to the inner surface of the fixed frame 60, a second portion 23b opposed to the inner side of the fixed frame 60 from the first portion 23a, and a first portion 23a. It has the connection part 23c which connected one end of the 1 part 23a and the 2nd part 23b gently. The first yoke 23 has an opening 230 at the other end of the first portion 23a and the second portion 23b. The third yoke 24 is attached at a position that closes the opening 230.

  The first magnet 22 is attached to the inner surface of the first portion 23 a of the first yoke 23 that is separated from the fixed frame 60. The second portion 23 b of the first yoke 23 is inserted into the first coil 21 in a non-contact state. The first coil 21 is not in contact with the first magnet 22. Therefore, the first coil 21 can move in the direction of the optical axis O along the second portion 23b of the first yoke 23 without contacting the surrounding members.

  Accordingly, when the first coil 21 is energized from a drive circuit (not shown), a magnetic field having a direction corresponding to the direction of the current is generated around the first coil 21, and the magnetic force is generated from the first magnet 22 to the first coil 21 by electromagnetic induction. The lens frame 11 is moved to one end side in the optical axis direction. Further, when the direction of the current supplied to the first coil 21 is changed, the lens frame 11 is moved to the other end side in the optical axis direction.

  On the other hand, an actuator 30 for driving the rear lens frame 12 includes a second coil 31 fixed to the outer edge portion of the lens frame 12, and is fixed to the fixed frame 60 side while facing the outside of the second coil 31. It includes a second magnet 32 provided, and a second yoke 33 that forms a second magnetic circuit in cooperation with the second magnet 32 and the second coil 31.

  The second yoke 33 has a U-shaped cross section in which an end on the side (rear side) separated from the first yoke 23 is folded, and has a structure in which a substantially rectangular magnetic plate is folded in half from the center. More specifically, the second yoke 33 includes a first portion 33a fixed to the inner surface of the fixed frame 60, a second portion 33b opposed to the inner side of the fixed frame 60 from the first portion 33a, and a second portion 33b. The first portion 33a and the second portion 33b have a connecting portion 33c that gently and integrally connects one end of the second portion 33b. The second yoke 33 is shorter in length along the optical axis O direction than the first yoke 23. The second yoke 33 has an opening 330 at the other end of the first portion 33a and the second portion 33b.

  The second magnet 32 is affixed to the inner surface of the first portion 33 a of the second yoke 33 that is separated from the fixed frame 60. The second portion 33 b of the second yoke 33 is inserted into the second coil 31 in a non-contact state. The second coil 31 is not in contact with the second magnet 32. For this reason, the second coil 31 is movable in the direction of the optical axis O along the second portion 33b of the second yoke 33 without contacting the surrounding members.

  Accordingly, when the second coil 31 is energized from a drive circuit (not shown), a magnetic field having a direction corresponding to the direction of the current is generated around the second coil 31, and the magnetic force from the second magnet 32 is applied to the second coil 31 by electromagnetic induction. Acts, and the lens frame 12 is moved to one end side in the optical axis direction. Further, when the direction of the current flowing through the second coil 31 is changed, the lens frame 12 is moved to the other end side in the optical axis direction.

  The intermediate member 40 is divided into two portions that are spaced apart from each other in the radial direction of the lens. The two portions of the intermediate member 40 are provided corresponding to the two sets of drive units of the actuators 20 and 30, respectively. Since the two portions of the intermediate member 40 have the same structure, only one of them will be referred to as the intermediate member 40 and will be described as a representative here.

  The intermediate member 40 is a plate-like member whose surface is painted black, for example, and is attached near the opening 230 of the first yoke 23, that is, at a position facing the inside of the third yoke 24. The intermediate member 40 is disposed along a plane orthogonal to the optical axis O. The intermediate member 40 has an inner edge 41 that is curved outward in accordance with the outer shape of the lenses of the movable lens groups 4 and 6 so as not to block useful light continuously passing through the movable lens group 4 and the movable lens group 6. The intermediate member 40 has two screw holes 42 and 43 near both ends in the longitudinal direction. Furthermore, the intermediate member 40 is integrally provided with a rib 44 for providing rigidity on at least one surface.

  Two buffer members 45 and 46 (first buffer members) are attached to the front surface 40a of the intermediate member 40. In the present embodiment, the buffer members 45 and 46 are provided at positions where a part of the front lens frame 11 moving along the first yoke 23 comes into contact. In other words, in this embodiment, the buffer member is not provided on the rear surface 40 b of the intermediate member 40. Furthermore, in other words, the buffer member may be provided only on one surface 40a (or 40b) of the intermediate member 40, and the number thereof is not limited to two.

  In the present embodiment, the buffer members 45 and 46 are attached to the intermediate member 40 to provide the buffer function. However, the present invention is not limited to this, and the intermediate member 40 itself may be formed of a material having a buffer function. In this case, it is effective to provide the intermediate member 40 with appropriate rigidity by providing the ribs 44.

Next, referring to FIG. 6 to FIG. 17, the structure for assembling each component 10, 20, 30, 40 of the assembly 50 described above into the fixed frame 60, and each component 10, 20 of the assembly 50. , 30, 40 will be described below.
FIG. 6 is a perspective view showing a fixed frame 60 attached to the inside of the outer frame 1 of the interchangeable lens 100. As shown in FIG. 2, the fixed frame 60 is integrated with the outer frame 1 in a state of being attached in the outer frame 1. For this reason, the fixed frame 60 also functions as a part of the outer frame 1. The fixed frame 60 is inserted and attached from the rear end side of the outer frame 1 in a state in which the assembly 50 is incorporated. Detailed description of the mounting structure and mounting method of the fixed frame 60 to the outer frame 1 will be omitted.

  The fixed frame 60 comes into contact with the inner wall of the first fixed portion 51 for fixing the first yoke 23, the second fixed portion 52 for fixing the second yoke 33, and the second yoke 33. A rectangular block-shaped protrusion 53 is provided between the first yoke 23 and the second yoke 33 to provide a gap along the optical axis O direction. The protrusion 53 forms a gap between the first yoke 23 and the second yoke 33 by bringing the second yoke 33 into contact with the end facing the first yoke 23.

  As described above, the actuators 20 and 30 for driving the movable lens groups 4 and 6 each have two sets of driving units that are separated from each other in the radial direction. For this reason, the fixed frame 60 also includes configurations 51, 52, and 53 for attaching the first yoke 23 and the second yoke 33 of the drive unit to two positions facing the radial direction of the inner wall thereof, respectively. Here, only one configuration will be described as a representative, and description of the other will be omitted.

  FIG. 7 is a perspective view showing the first yoke 23 attached to the first fixing portion 51 of the fixed frame 60, and FIG. 8 shows a state where the first yoke 23 is attached to the first fixing portion 51 of the fixing frame 60. FIG. 9 is a partial cross-sectional view taken along line F9-F9 in FIG. The first yoke 23 includes a first magnet 22 on the inner surface of the first portion 23a. The first magnet 22 is bonded and fixed to the first portion 23a. The first portion 23a includes two through holes 23d for injecting adhesive.

  First, the first yoke 23 including the first magnet 22 is attached to the first fixing portion 51 of the fixed frame 60. At this time, the first yoke 23 is inserted into the fixed frame 60 with the connecting portion 23c at the top such that the first portion 23a faces the first fixed portion 51 of the fixed frame 60. Then, the boss 23 e protruding from the outer surface of the first portion 23 a of the first yoke 23 is fitted into the positioning hole 51 a provided in the first fixing portion 51 of the fixed frame 60, and the first yoke 23 is attached to the fixed frame 60. Position with respect to. Further, the screw 54 is inserted from the outside of the fixed frame 60 through the screw insertion hole 51 b and screwed into the screw hole 23 f provided on the outer surface of the first portion 23 a of the first yoke 23. As a result, the first yoke 23 including the first magnet 22 is fixed to the first fixing portion 51 of the fixed frame 60.

  Next, as shown in FIG. 10, a lens frame 11 holding the front movable lens group 4 is attached. At this time, the fitting groove 11 a of the lens frame 11 is fitted to the guide shaft 13, the guide shaft 14 is inserted into the through hole 11 b of the lens frame 11, and the first coil 21 fixed to the lens frame 11 is inserted into the first coil 21. The second portion 23b of the one yoke 23 is inserted. In this state, the movement of the lens frame 11 in the direction orthogonal to the optical axis O direction is restricted by the two guide shafts 13 and 14, so the first coil 21 is not in contact with the first yoke 23. The state is maintained.

  Next, the third yoke 24 is attached so as to close the opening 230 behind the first yoke 23. FIG. 11 is a perspective view of the third yoke 24 as viewed from the second yoke 33 side. The third yoke 24 is a plate-like magnetic body having a constant thickness, and includes two rectangular sheet-like nonmagnetic members 25 having a uniform thickness on a surface 24 a facing the second yoke 33. The two nonmagnetic members 25 are affixed to the surface 24 a so as to be separated from each other in the longitudinal direction of the third yoke 24.

  As shown in FIG. 12, the third yoke 24 is attached in contact with the end of the first yoke 23 that faces the second yoke 33. The third yoke 24 is magnetically attracted to the first yoke 23 by the magnetic force of the first magnet 22. In other words, the third yoke 24 does not adhere to the first yoke 23. The third yoke 24 has a notch 24b for releasing the protrusion 23g protruding from the end of the first portion 23a of the first yoke 23 and a protrusion 23h protruding from the end of the second portion 23b of the first yoke 23. It has a notch 24c for escaping. And the inner surface of each notch 24b, 24c contacts each protrusion 23g, 23h, and is magnetically attracted | sucked. The third yoke 24 is attached to the first yoke 23 and is separated from the first magnet 22 as shown in FIG.

  Next, as shown in FIG. 13, the intermediate member 40 is attached. The intermediate member 40 is inserted and arranged from the rear end side of the fixed frame 60 so that the surface 40a to which the buffer members 45 and 46 are attached faces the lens frame 11. Then, the intermediate member 40 is fastened and fixed to the fixed frame 60 by inserting the two screws 47 and 48 into the screw holes 42 and 43 of the intermediate member 40 and screwing them into the fixed frame 60. The intermediate member 40 is disposed between the movable region along the optical axis O direction of the lens frame 11 and the movable region along the optical axis O direction of the lens frame 12. The intermediate member 40 is attached to peripheral members other than the fixed frame 60 in a non-contact state.

  The buffer members 45 and 46 (not shown in FIG. 13) attached to the front surface 40a of the intermediate member 40 are formed on a part of the lens frame 11 when the front lens frame 11 moves to the rear end of the movable region. It absorbs the shock by contact. On the other hand, when the rear lens frame 12 moves to the front end of the movable region, a buffer member for contacting the lens frame 12 and absorbing the impact is required. In the present embodiment, the buffer members 61 and 62 (second buffer members) that absorb the impact caused by the contact of the lens frame 12 are attached to the fixed frame 60. The layout of the buffer members 61 to 66 provided on the fixed frame 60 will be described later.

  As in the present embodiment, buffer members 45 and 46 for the front lens frame 11 are provided on one surface 40a of the intermediate member 40, and the buffer member is not provided on the other surface 40b. Is provided with buffer members 61 and 62 for the rear lens frame 12 in a separate fixed frame 60, so that when the two lens frames 11 and 12 move to the end portions of the movable regions facing each other, The impact when the lens frame 11 (12) collides can be prevented from being transmitted to the other lens frame 12 (11).

  After attaching the intermediate member 40, the lens frame 12 holding the rear movable lens group 6 is attached as shown in FIG. At this time, the fitting groove 12 a of the lens frame 12 is fitted to the guide shaft 13, and the guide shaft 15 is inserted into the through hole 12 b of the lens frame 12. Accordingly, the movement of the lens frame 12 in the direction orthogonal to the optical axis O is restricted by the two guide shafts 13 and 15, and the lens frame 12 is positioned.

  Next, the second yoke 33 is attached to the second fixing portion 52 of the fixing frame 60. As shown in FIG. 15, the second yoke 33 includes a second magnet 32 on the inner surface of the first portion 33a. The second magnet 32 is bonded and fixed to the first portion 33a. The first portion 33a has two through holes 33d for injecting adhesive.

  As shown in FIG. 16, the second yoke 33 including the second magnet 32 has a front end portion spaced from the coupling portion 33 c in a direction in which the first portion 33 a faces the second fixing portion 52 of the fixing frame 60. That is, it is inserted into the fixed frame 60 with the opening 330 at the top. That is, in this state, the opening 230 of the first yoke 23 and the opening 330 of the second yoke 33 face each other.

  At this time, the second portion 33 b of the second yoke 33 is inserted into the second coil 31 fixed to the lens frame 12. Then, the protrusion 53 of the fixed frame 60 is fitted into and abuts with a notch 33e provided at the end of the first portion 33a spaced from the connecting portion 33c, and the second yoke 33 is positioned with respect to the fixed frame 60. . In this way, a part of the second yoke 33 abuts on the protrusion 53, thereby preventing the second yoke 33 from contacting the first yoke 23.

  Thereafter, as shown in FIG. 17, the screw 55 is inserted from the outside of the fixed frame 60 through the screw insertion hole 52 a and screwed into the screw hole 33 f provided on the outer surface of the first portion 33 a of the second yoke 33. As a result, the second yoke 33 including the second magnet 32 is fixed to the second fixing portion 52 of the fixed frame 60. Through the above steps, the constituent elements 10, 20, 30, and 40 of the assembly 50 are assembled into the fixed frame 60.

  Here, the layout of the buffer members 45, 46, 61 to 66 will be described with reference to FIGS. 18 is a perspective view for explaining a layout of the buffer members 45 and 46 attached to the intermediate member 40 and the buffer members 61 to 64 attached to the fixed frame 60. FIG. , 61 to 66 are cross-sectional views for explaining the layout. In FIG. 18, the lens frames 11 and 12 are not shown in order to make the positions of the buffer members 45, 46 and 61 to 66 easier to see, and in FIG. 19, the actuators 20 and 30 are further omitted. ing.

  The buffer members 45 and 46 are attached to the front surface 40a of the intermediate member 40 as described above. These two buffer members are provided at positions where the front lens frame 11 can contact the rear surface of the lens frame 11 and absorb an impact when the front lens frame 11 moves to the rear end of the movable region. Further, as described above, when the rear lens frame 12 moves to the front end of the movable region, the buffer members 61 and 62 are in positions where they can contact the front surface of the lens frame 12 and absorb the impact. Is attached to the fixed frame 60.

  Further, the buffer members 63 and 64 are provided at positions where the front lens frame 11 can contact the front surface of the lens frame 11 and absorb an impact when the front lens frame 11 moves to the front end of the movable region. . Further, the buffer members 65 and 66 are provided at positions where the rear lens frame 12 can contact the rear surface of the lens frame 12 and absorb an impact when the rear lens frame 12 moves to the rear end of the movable region. .

  As described above, by laying out the buffer members 45, 46, 61 to 66, the impact when the lens frame 11 collides with the buffer members 45 and 46 and the impact when the lens frame 12 collides with the buffer members 61 and 62. The trouble that the impact is transmitted to each other can be prevented, and the operation sound of the actuators 20 and 30 can be reduced.

  In the present embodiment, buffer members 45 and 46 (first buffer members) for bringing the rear end of the lens frame 11 into contact with the front surface 40 a of the intermediate member 40 are provided, and the front end of the lens frame 12 is provided on the fixed frame 60. However, the present invention is not limited to this, and the buffer member 45 that brings the front end of the lens frame 12 into contact with the rear surface 40b of the intermediate member 40 is described. 46 (first buffer member) may be provided, and buffer members 61 and 62 (second buffer member) for bringing the rear end of the lens frame 11 into contact with the fixed frame 60 may be provided. In any case, it is only necessary to provide the buffer member only on one surface without providing the buffer member on both surfaces of the intermediate member 40.

  Next, the diaphragm function of the intermediate member 40 will be described with reference to FIGS. As described above, the intermediate member 40 has a function of partitioning the space between the movable area of the front lens frame 11 and the movable area of the rear lens frame 12, as well as from a subject (not shown) incident on the fixed frame 60. It has a function of shielding unnecessary light from light from being transmitted from the first movable region to the second movable region.

  20 is a view of the assembly 50 with the front lens frame 11 removed, as viewed from the front, and FIG. 21 is a view of the assembly 50 with the rear lens frame 12 removed, as viewed from the rear. is there. 22 and 23 are partial enlarged cross-sectional views in which main parts of the assembly 50 are enlarged. As shown in FIGS. 20 to 23, the intermediate member 40 is attached in contact with the inner surface of the second portion 23b of the first yoke 23, and there is no gap therebetween.

  For this reason, as shown in FIG. 22, the intermediate member 40 has light incident on the second movable region from the first movable region via the gap between the second portion 23 b of the first yoke 23 and the first coil 21. Can be shielded from light. Further, as shown in FIG. 23, the intermediate member 40 can shield light that is reflected by the inner surface of the second portion 23 b of the first yoke 23 and enters the second movable region. Thus, unnecessary light reflected by the yoke or reflected by the yoke adversely affects the photographed image of a camera (not shown). Can be provided.

  FIG. 24 is a ray diagram of light incident on the fixed frame 60. According to this, due to the diaphragm function of the intermediate member 40, light that has passed through the front movable lens group 4 and light that has passed through the gap of the coil that does not directly pass through the movable lens group 6 or light reflected by the yoke is unnecessary. You can see that most of the light is blocked.

  The length of the movable region of the front lens frame 11 along the optical axis O direction is determined by the length of the second portion 23b of the first yoke 23 of the actuator 20 in the optical axis O direction, and the movable of the rear lens frame 12 is movable. The length of the region along the optical axis O direction is determined by the length of the second portion 33 b of the second yoke 33 of the actuator 30 in the optical axis O direction. In other words, the position along the optical axis O direction of the intermediate member 40 that partitions the two movable regions is determined by the length of the first and second yokes 23 and 33 along the optical axis O direction. For this reason, from a different viewpoint, the intermediate member 40 is disposed at a position that performs the best diaphragm function, and the lengths of the first and second yokes 23 and 33 are designed in accordance with the position of the intermediate member 40. You can also.

  As described above, according to the interchangeable lens 100 of the present embodiment, an intermediate member having both a partition (buffer) function and a diaphragm function between the movable region of the front lens frame 11 and the movable region of the rear lens frame 12. Since 40 is disposed, the number of parts can be reduced, assembly can be facilitated, and optical characteristics can be improved.

  Further, according to the present embodiment, the first yoke 23 (and the third yoke 24) of the actuator 20 and the second yoke 33 of the actuator 30 are separated from each other in the direction of the optical axis O. During the operation of (30), it is possible to prevent the magnetic force as a noise component from acting on the other actuator 30 (20) by mutual induction, and to drive and control the two sets of movable lens groups 4 and 6 accurately. . The nonmagnetic member 25 disposed between the first yoke 23 and the second yoke 33 functions to reduce the influence of magnetic force due to mutual induction.

  Further, according to the present embodiment, since the first yoke 23 and the second yoke 33 are U-shaped, it is possible to easily attach the yokes 23 and 33 without providing an opening on the side surface of the outer frame 1. Workability can be improved. In addition, since an undesired opening is not provided in the outer frame 1, the rigidity of the outer frame 1 can be maintained, and the mechanical strength of the interchangeable lens 100 can be increased.

  Furthermore, according to the present embodiment, since the third yoke 24 is not bonded to the first yoke 23, the number of assembly steps can be reduced, the waiting time until the adhesive is cured can be eliminated, and the manufacturing cost of the interchangeable lens 100 can be reduced. Can be reduced.

  In addition, this invention is not limited to embodiment mentioned above, It can change arbitrarily, without exceeding the range of invention.

  DESCRIPTION OF SYMBOLS 1 ... Outer frame, 4, 6 ... Movable lens group, 10 ... Supporting mechanism, 11, 12 ... Lens frame, 13, 14, 15 ... Guide shaft, 20, 30 ... Actuator, 21 ... First coil, 22 ... First Magnets 23 ... first yoke 24 ... third yoke 25 ... non-magnetic member 31 ... second coil 32 ... second magnet 33 ... second yoke 40 ... intermediate member 45, 46 ... buffer member DESCRIPTION OF SYMBOLS 50 ... Assembly, 51 ... 1st fixing | fixed part, 52 ... 2nd fixing | fixed part, 53 ... Protrusion, 60 ... Fixing frame, 61-66 ... Buffer member, 100 ... Interchangeable lens, 230, 330 ... Opening, O ... Light axis.

In one aspect of the lens barrel of the present invention, the first movable member holding the first lens group and the second movable member holding the second lens group are arranged in the optical axis direction so as to be movable with respect to the fixed frame. A lens barrel comprising a first coil, a first magnet disposed opposite to the first coil, and a U-shaped first yoke to form a first magnetic circuit, and the first magnetic circuit The first actuator is configured to move the first movable member in the optical axis direction, the second coil, the second magnet disposed to face the second coil, and the U-shaped second yoke. A second magnetic circuit that is magnetically independent of the second magnetic circuit, and a second actuator that moves the second movable member in the optical axis direction by the second magnetic circuit; and the first movable member; Located between the second movable member, An intermediate member having a diaphragm portion serving as a diaphragm of an optical system including the first lens group and the second lens group, and a collision preventing portion for preventing the first movable member and the second movable member from colliding with each other. The opening of the U-shaped first yoke and the opening of the U-shaped second yoke are spaced apart from each other by a predetermined distance, and are opposed to each other. An opening edge having a predetermined diameter for shielding unnecessary light passing through a gap between the first coil and the first yoke and unnecessary light reflected by the first yoke is provided.

The intermediate member 40 is a plate-like member whose surface is painted black, for example, and is attached near the opening 230 of the first yoke 23, that is, at a position facing the inside of the third yoke 24. The intermediate member 40 is disposed along a plane orthogonal to the optical axis O. The intermediate member 40 has an inner edge 41 (opening edge) curved outward to match the outer shape of the lenses of the movable lens groups 4 and 6 so as not to block useful light continuously passing through the movable lens group 4 and the movable lens group 6. Part) . The intermediate member 40 has two screw holes 42 and 43 near both ends in the longitudinal direction. Furthermore, the intermediate member 40 is integrally provided with a rib 44 for providing rigidity on at least one surface.

In addition, this invention is not limited to embodiment mentioned above, It can change arbitrarily, without exceeding the range of invention.
Hereinafter, the invention described in the scope of claims at the beginning of the application of the present application will be added.
[1]
A lens barrel that houses a first movable member holding a first lens group and a second movable member holding a second lens group in an optical axis direction so as to be movable relative to a fixed frame,
The first coil, the first magnet disposed opposite the first coil, and the first yoke form a first magnetic circuit, and the first magnetic circuit moves the first movable member in the optical axis direction. A first actuator to be moved to
The second coil, the second magnet disposed opposite to the second coil, and the second yoke constitute a second magnetic circuit magnetically independent of the first magnetic circuit, and the second coil A second actuator for moving the second movable member in the optical axis direction by a magnetic circuit;
A diaphragm portion located between the first movable member and the second movable member and serving as a diaphragm of an optical system including the first lens group and the second lens group, the first movable member, and the second movable member. An intermediate member having a collision preventing part for preventing the member from colliding;
A lens barrel characterized by comprising:
[2]
The lens barrel as set forth in [1], wherein the first yoke and the second yoke are spaced apart from each other by a predetermined distance in the optical axis direction.
[3]
On the first movable member side of the intermediate member, a first buffer member for absorbing an impact caused by the collision of the first movable member is provided,
The fixed frame at the end of the movable region of the second movable member on the intermediate member side is provided with a second buffer member for absorbing an impact caused by a collision of the second movable member. The lens barrel according to [1].

Claims (3)

A lens barrel that houses a first movable member holding a first lens group and a second movable member holding a second lens group in an optical axis direction so as to be movable relative to a fixed frame,
The first coil, the first magnet disposed opposite the first coil, and the first yoke form a first magnetic circuit, and the first magnetic circuit moves the first movable member in the optical axis direction. A first actuator to be moved to
The second coil, the second magnet disposed opposite to the second coil, and the second yoke constitute a second magnetic circuit magnetically independent of the first magnetic circuit, and the second coil A second actuator for moving the second movable member in the optical axis direction by a magnetic circuit;
A diaphragm portion located between the first movable member and the second movable member and serving as a diaphragm of an optical system including the first lens group and the second lens group, the first movable member, and the second movable member. An intermediate member having a collision preventing part for preventing the member from colliding;
A lens barrel characterized by comprising:   2. The lens barrel according to claim 1, wherein the first yoke and the second yoke are spaced apart from each other by a predetermined distance in the optical axis direction. On the first movable member side of the intermediate member, a first buffer member for absorbing an impact caused by the collision of the first movable member is provided,
The fixed frame at the end of the movable region of the second movable member on the intermediate member side is provided with a second buffer member for absorbing an impact caused by a collision of the second movable member. The lens barrel according to claim 1.